Long-term smokers in Australia find the taste of plain-packaged cigarettes to be worse than branded cigarettes, new research suggests.
A study of 51 smokers by the University of Newcastle also found that participants can no longer differentiate between brands, saying that all cigarettes now tasted the same.
Tobacco companies have denied changing ingredients, and co-author and PhD candidate Ashleigh Guillaumier said the study's findings highlights the power of branding.
"It's one of the main reasons that the tobacco industry fought so hard against the introduction of plain packs," said Ms Guillaumier.
"They have spent a lot of time building up their branding and know how influential it is on people's perceptions and experience of the product."
The researchers investigated the impact of the new one-colour packets dominated by vivid health warnings by conducting group discussions with smokers before and after plain packaging was implemented in 2012.
"They couldn't discern a difference between brands now and they thought the quality of the tobacco had deteriorated.
"That was a consistent talking point that people really agreed on in the groups sessions."
Co-author Associate Professor Billie Bonevski said the study lends support to the plain packaging legislation and provides fuel for other countries to take up the policy.
Plain packaging became mandatory in Australia on December 1, 2012.
The University of Newcastle study is published in Health Education Research (Oxford University Press).